The Fairfax, Va.-based subsidiary of NiSource Gas Transmission is proposing to install an 8.9-mile expansion “loop” from the Eagle Compression Station in Upper Uwchlan to the Downingtown Compression Station in West Bradford, tying into the company’s existing pipeline.

According to the commission, the assessment will discuss the environmental impact the pipeline could have, and it will be used to help the commission decide whether to approve the project.

The beginning of the assessment also marks the start of the “scoping” process, during which the commission will gather feedback about the project from the public and any interested agencies. The scoping process will end July 8.

During this time, Columbia, owned by NiSource, might contact landowners to discuss whether they can secure easements on land in the project’s path. Easements would allow the company to construct, operate and maintain pipeline facilities.

According to the commission, if the project is approved, it is also given the power of eminent domain, allowing Columbia to condemn properties where they could not reach an agreement about compensation for the owners.

The commission has been informed of environmental issues during the pre-filing process, which include potential impacts on residences near the project’s right of way, possible effects from multiple pipelines on a single property, tree clearing, erosion and sediment control, and the potential effects the project might have on the area’s water quality.

The assessment will study the area’s geology, soils, water resources, fisheries, wetlands, vegetation and wildlife, endangered and threatened species, cultural resources, land use, socioeconomics, air quality, noise, reliability and safety, and the cumulative environmental impact that the project could have.

According to Maya Van Rossum, spokeswoman for the Delaware Riverkeeper Network, the project also has the potential to increase the amount of water runoff due to soil compaction.

“That means more water rushing off during rain events, being dumped into creeks, and downstream communities, increasing flooding and erosion that communities have to then respond to and contend with,” Van Rossum said.

The next public meeting about the project in Chester County will begin at 7 p.m. June 18 at West Chester University’s Sykes Auditorium.

Comments about the project can be presented at the meeting or sent to the commission by July 8, either electronically, through the commission’s website, www.ferc.gov, or by mailing them to: Kimberly D. Bose, Secretary, Federal Energy Regulatory Commission, 888 First St. NE, Room 1A, Washington, D.C., 20426.

The 26-inch diameter pipeline would run parallel to an existing pipeline. The natural gas pipeline project would affect about 180 Chester County landowners in its right-of-way once construction begins. It will cut through area wetlands and waterways, including the Brandywine Creek, which will be crossed using the horizontal directional drilling method.

According to Brian Luis, project engineer, the company decided to expand instead of replacing the existing pipeline with one of a larger diameter because a replacement would cause an interruption in service to customers.

NiSource is currently in the pre-filing process for the project with the Federal Energy Regulatory Commission. The purpose of the pre-filing process is to allow stakeholder and environmental issues to be identified and resolved early.

According to John Peconom, spokesman for the commission, pre-filling usually takes about six months, at which point the gas company would file their application.

The pipeline is part of Columbia’s Side Expansion project, which will feature looping pipelines in Chester County and in Gloucester County, N.J.

According to the pre-filling request, improvements to the Eagle Compressor Station in Chester Springs will include installation of additional piping and valves.